Warren Buffett, 83-year-old billionaire, met a roomful of twenty-something Georgetown University students Thursday,and gave them simple investment advice: You can get wealthy with just a few good investment choices.

Buffett was speaking at a question-and-answer session hosted by Bank of America CEO Brian Moynihan. The event was part of a partnership between Georgetown's Global Social Enterprise Initiative at the University's McDonough School of Business and Bank of America.

When one student asked for a stock tip, Buffett, widely considered the most successful investor of the 20th century, gave him a simple answer: Buy a copy of The Intelligent Investor, the investing bible written by Benjamin Graham, father of value investing. That and two wedding licenses, Buffett said, were his best investments.

But, the chairman and CEO of Berkshire-Hathaway said, you don't need to make hundreds of investments -- just a few, made at the right time. "Most stocks at some point sell at very silly prices," Buffett said.

One of the most recent times: Five years ago, during the financial meltdown. "Whatever you think about it [the meltdown], it was worse," Buffett said, saying Federal Reserve Chairman Ben Bernanke, Treasury Secretary Henry Paulson and Timothy Geithner, then president of the New York Federal Reserve Bank deserved credit for saving the economy. He also gave special credit to President George W. Bush, although he didn't vote for him.

"Bush came out with the economic insight for all times, and in 10 words," Buffett, said. "He said, 'If money isn't loose enough, this sucker could go down.'"

Buffett also advised students to stick with companies and industries that they know. "The most important thing is deciding what industries you can be right about," he said. Bill Gates couldn't convince him about computers, he said, but he did understand that people would continue to chew gum and drink soft drinks. "I'll stick with chewing gum," he said. "It's a terrible mistake to think you have to have an opinion on everything."

Buffett's optimism was clear throughout. "If you look at the twentieth century, with two wars, the Spanish influenza, and the Great Depression, and the Dow went from 66 to 11,497. With all those terrible things happening, America works."

But, he said, income inequality is a growing problem and needs to be addressed by government. "The rich are doing extremely well, businesses are doing well, profit margins are terrific compared with historic levels, but the for the bottom 20%, 24 million people, the top income is $22,000. We haven't learned how to let everyone share the bounty that we have."

And Buffett reflected on his time in Washington as a student at Woodrow Wilson High School during World War II. His father, Howard Buffett, was a Congressman. "It was a window on an extraordinary time in American history," Buffett said. "We were more untied than any other time in my lifetime. People really did give up voluntarily a high percentage in terms of gas rationing, sugar and beef rationing -- we all bought savings bonds at school.

And, he said, as a paperboy, he delivered papers at the local hospital -- a favorite location because the patients tipped, in more ways than one. "The numbers racket was big in Washington," he said.